The present invention generally relates to a fluid level regulator. More particularly, the present invention relates to an oil level regulator for controlling the oil level in a compressor crankcase.
Mechanical oil level control systems and regulators are generally known for controlling the oil level in a compressor crankcase. For example, U.S. Pat. No. 2,246,244 discloses a prior oil level control system for a refrigeration compressor. An oil level regulator is desirably capable of adjusting the oil level of the associated crankcase within predetermined oil level limits. The oil regulator disclosed in the aforementioned patent is not adjustable.
Adjustable mechanical regulators are generally known. U.S. Pat. No. 4,428,208, incorporated herein in its entirety, relates to such a device. That device includes a float which is connected at its side to a pivotable lever. Responsive to the oil level, the float travels along an arc, the float motion being constrained by the attached lever. The lever is operable to open or close a valve to control a flow of oil through an inlet. The inlet includes a vertically adjustable piston to which the valve, lever and float assembly are attached. This assembly is adjustable with a separate adjustment pin which extends vertically through the top of the regulator housing to the valve. The pin is threaded to the valve so that rotation of the pin from outside the regulator causes vertical adjustment of the valve assembly. Because the float has an amount of horizontal travel along its arc, the width of the conventional regulator must be sized accordingly. Therefore, a regulator design is desirable which is compact and simple to adjust.
While conventional oil level regulators provide inflow of fluid when needed, such regulators do not provide an active signal indicating a seriously low oil condition. Such a low level condition could result where supply oil flow to the regulator is terminated or blocked or where a leak exists in the compressor crankcase. Known regulators have a sightglass which provides a visual indication of the actual oil level. However, such a sightglass indicator might go unnoticed in some environments. Therefore, it is desirable to provide an improved oil level regulator which reliably signals a low-oil condition with an active indicator. Accordingly, it is also desirable to terminate system operation below a certain critically low oil condition.
In a compressor system having an oil pump, oil loss can be detected by loss of oil pressure. However, certain compressor systems do not have an oil pump. In such systems, another means must be used to detect a low oil condition. It is therefore desirable to provide an improved regulator which is compatible with a such a pumpless compressor system.